Test and measurement instruments are fundamental to analyzing the quality of electrical signals. Such instruments allow a variety of industries to develop and test new products, maintain quality control, and deliver high value products and services. Industries such as computers, electronics, video, entertainment, and industrial manufacturing, among others, rely heavily on the ability to efficiently test and analyze electrical signals.
For instance, in the video production and broadcasting industry, video signal analysis and comparison is essential to the successful delivery of high-quality video. Multiple cameras are often necessary, and it can be difficult to adjust these to have the same luminance and chrominance levels for the video recording stage. In studios, video producers need to verify that particular changes occurred at a given time and position after the video is edited. Broadcast stations must maintain certain quality and characteristics for video distribution and real-time processing. Equipment and distribution trouble-shooting also requires comparisons of video from different inputs, outputs, and transmission points.
Conventionally, video signal comparisons are carried out using multiple video waveform monitors connected to different video signals. Alternatively, one waveform monitor might be used with input signal switches at the front end. An operator typically sets up the waveform monitor for one specific measurement display, and then performs visual comparison on multiple waveform monitors, or otherwise displays and compares one output at a time. Some waveform monitors such as the Tektronix® WFM7000/6000 and WVR7000/6000 series monitors, support video comparison between previously frozen or captured traces and live signals.
However, there are inherent drawbacks, difficulties, and unreliability associated with the traditional comparison methods for video signals. Configuring multiple video waveform monitors to have the same measurement display with identical settings is very tedious and error prone because measurement displays most often require that multiple parameters be set, including filters, component selections, gains settings, and so forth. Moreover, comparing a previously captured display with a live measurement display is also prone to result in confusion or error and is not reliable. Such approaches unavoidably miss the dynamic characteristics of video signals.